Water Resource

Quality Monitoring

VOLUME 1

sampling protocol for

Inorganic chemical analysis

Resource Quality Services Department of Water Affairs

November 2004

Water Resource Quality Monitoring Volume 1: Inorganic chemical analysis

Copyright © 2004 Department of Water Affairs All rights reserved

ISBN: 2-621-35123-7

This publ ication is available from:

The Director Resource Qual ity Services Private Bag X313 Pretoria 0001

Tel 012 808 9500 Faks 012 808 2702

The Task Team

Annelise Gerber - layout, photographs, text Philip (Gansie) van Deventer- sampl ing protocol , text Alfred Seloana - sampling techniques Brendan Hohls - editing, text

Printing and binding Government Printers , Pretoria

Contents

Page Purpose of this monitoring guide 2 Introduction 3

Inorganic Chemical Analysis 1 . The monitoring network 5 2. Where to collect samples 6

2. 1 from a dam 7 2.2 from a river without gauging structure 8 2. 3 from a river with a gauging structure 9

3. Sampling frequency 1 0 4. Preparation & cleaning of sample 11

bottles 5. General considerations regarding 12

sampling 6. How to take a sample: 14

• macro sample 1 5 • trace metal sample 16 • turbidity sample 1 7 • sampling from a boat 1 8 • sampling from a dam wall 1 9 • sampling in a river 20

7. Temperature measurements 21 8. How to preserve a sample 22 9. Important warning 23

Purpose of this monitoring guide

This Water Quality Monitoring guide is designed to be easy to use, with step by step instructions on the procedures to follow when collecting samples for specific programmes.

The guide is to be used by RQS personnel, regional officers and private monitors who need to collect data regarding the aquatic environment.

The guide also highlights problems and mistakes commonly associated with water quality monitoring.

-. Water qualitY monitoring is an activity to , collect-information on the physical, chemical

and biological characteristics of a water resource, be it a river, dam, estuary, wetland or: subterraneous ground water. ' ·~ ....

Monitoring consists of 3 steps: i) Data acquisition

ii) Data storqge & manipulation - iii) lnformation'generation & dissemination

. ~ This guide. ~ddresses only the first component, namely, the ·data acquisition phase.

INORGANIC CHEMICAL ANALYSIS

1. THE MONITORING NETWORK:

The National Chemical Monitoring Network is currently the largest network running at the RQS. Three types of samples are collected for this program.

The MACRO SAMPLE This is the most common type of sample which is taken and analysed for major inorganic ions. The ions most commonly found in natural waters are the cations calcium, magnesium, sodium and potassium, and the anions bicarbonate, carbonate, chloride and sulphate (Dallas & Day, 1993) The results provide an indication of the ion balance and the inorganic chemical water quality of a water resource (dam, river etc.)

The TURBIDITY SAMPLE Turbidity relates to how transparent water is. Turbid water is caused by suspended matter, such as clay, silt, fine organic and inorganic matter, soluble coloured organic compounds, plankton and other microscopic organisms that are held in suspension (Harris et al., 1992)

The TRACE METAL SAMPLE This is the 1ype of sample which is analysed for metals that normally occur in very small (trace) quantities but their presence can either be beneficial, troublesome or toxic. The results, depending on the fraction that was analysed, will give an indication of metals that were dissolved or suspended in the water

2. WHERE TO COLLECT SAMPLES: A clear distinction should be made between samples collected from flowing sources and samples collected from standing water.

STANDING WATER ,.. Dams ,.. Lakes ,.. Pans

CONTINUE SAMPLING REGARDLESS OF INFLOW

FLOWING WATER ,.. Rivers ,.. Canals

STOP SAMPLING WHEN YOU OBSERVE NO FLOW

2.1 Collecting samples from a dam:

,. There can be more than one sampling point on a dam.

,. Points are differentiated by adding a Q number after the dam number e.g. A2R009Q02.

,. Point QOl is always opposite the middle of the dam wall, and about 50-1 00 meters away from the wall.

2.2 Collecting samples from a river without

,.. Never sample on one side of an island. Make sure to

,.. When sampling downstream of a confluence, remember to select a point where water from both ports of the stream are thoroughly mixed.

2.3 Collecting samples from a river with a measuring/gauging structure:

~ The ideal place to sample is directly below the weir where the water flows through.

,. Turbidity samples are collected where the water is most turbulent (fast and well mixed).

,. When the weir Is flooded, it is safer to collect the sample downstream from the weir where water is still thoroughly mixed.

3. SAMPLING FREQUENCY:

.. Sampling should take place at an optimum frequency, which are determined by Resource Quality Services. Data collectors are notified accordingly.

partmenl of Water Affairs and Forestry MONITORING SCHEDUL

msdb@inf_OS_iwqs

THIS MONITORING SCHEDULE IS EFFECTIVE FOR THE PERIOD 2003-10-21 TO 2003·12·31 AND REPLACES Al

Monitor: DEPARTMENT OF WATER AFFAIRS AND FORESTRY· RESOURCE QUALITY SERVICES

Monitoring Monitoring Point Start & End Action Monitoring Somple Container PointlD Name Date Frequency Action Type

90240 A2R001QJI 1999-02-01 2 WEEKLY 25M FIXED MACRO- 350Ml WHITE/ HARfBEESPOORT 2009-12·31 ACTION DEPiHGRAB RQS BLUE PLASTIC DAM ON FREQUENC SAMPLE MACR CROCODILE RIV: y

NEAR DAM WALL

90240 A2ROOJQJ1 1999·02.01 2 WEEKLY 25M FIXED ALGAL IOOOML WHITE HARTBEESPOORT 2C09·12·31 ACTION DEPiH GRAB ID-RQS PLASTIC 8011-810 DAM ON FREQUENC SAMPLE LAB CROCODILE R/V: y PREPARAT NEAR DAM WALL

90240 A2ROOIQJ1 1999-!0·15 2WEEKLY 15M FIXED HVDROBI 1000ML WHJTE HARTBEESPOORT 2004-06-30 ACTION DEPTH GRAB OLOGICA PLASTIC 8011-810 DAM ON FREQUENC I SAMPLE L-RQS LAB CROCODILE RIV: V PREP. NEAR DAM WAll

90240 A2ROOIQJI 19\'-9- 1(). 15 2WEEKLV 1Mf/XED HYDROS/ IOOOML WHITE HARfBEESPOORT 2004-06-30 ACT!ON DEPTH GRAB OLOGICA PLASTIC 8011-810 DAM ON FREQUENC SAMPLE l·RQS LAB CROCODILE RIV: V PREP. NEAR DAM WAl l

I .. An example of a monitoring schedule showing the sampling

frequency.

4. PREPARATION AND CLEANING OF SAMPLE BOTTLES:

,.. Sample bottles must be l 00% clean.

,.. Sample bottles are washed with special phosphate free cleaning agents.

,.. Do not use any bottles that were washed with ordinary dishwashing soap otherwise the results may not be valid.

5. GENERAL CONSIDERATIONS REGARDING SAMPLING:

THIS MONITORING SCHEDULE IS EFFECTIVE FOR THE P

Monitor: DEPARTMENT OF WATER AFFAIRS AND FOF

Monitoring Monitoring Point Start & End Actlor Point ID Name Dole Frequ<

90240 A2R001Q01 1999-02-01 2WEH HARTBEESPOORT 2009-12-31 ACTIO DAM ON FREQU CROCODILE RIV: V NEAR DAM WALL

,. Make sure that the sample is listed on the monitoring schedule

,. Make sure that you have the correct sample bottles.

,. Make sure that you have the correct tags at hand

,. Do not store samples on the windowsill. Even preserved samples can deteriorate.

~ Never sample from a tap unless you are instructed to do so

~ Keep all your sampling equipment clean, do not use for anything else!

~ Do not use sample bottles as storage jars or candle holders or ashtrays!

The macro sample:

Leave the lid on the bottle until you are ready to take the sample. Collect a little bit of water and rinse the bottle. Pour the water out. away from where the sample will be taken.

Now collect the sample by lowering the bottle into the water. Perform a forward scoop motion if the boat is not moving.

Do not fill the bottle right up to the top. Leave space for the preservative.

Preserve the sample with one ampoule containing Mercury chloride. Break ampoule and then drop both pieces into the bottle. (see page 21 )

Fill out the correct tag as received from Resource Quality Services and fasten around the neck of the bottle with a piece of string.

Store sample in a cooler box or dark container

The trace metal sample:

Leave the lid on the bottle until you are ready to take the sample. Collect a little bit of water and rinse the bottle. Pour the water out away from where the sample will be taken.

Now collect the sample by lowering the bottle into the water. Perform a forward scoop motion if the boat is not moving.

Fill the bottle to the top.

DO NOT ADD PRESERVATIVE

Fill out the correct tag as received from Resource Quality Services and fasten around the neck of the bottle with a piece of string.

Store sample in a cooler box or dark container

The turbidity sample:

Leave the lid on the bottle until you are ready to take the sample. Collect a little bit of water and rinse the bottle. Pour the water out, away from where the sample will be taken.

Now collect the sample by lowering the bottle into the water.

--

Perform a forward scoop motion if the boat is not moving.

Fill the bottle to the top.

DO NOT ADD PRESERVATIVE

Fill out the correct tag as received from Resource Quality Services and fasten around the neck of the bottle with a piece of string.

Store sample in a cooler box or dark container

_ ....... _

=

Collect the sample by lowering the bottle into the water, Perform a forward scoop motion if the boat is not moving.

or

Use a beaker to collect water and then pour into the sample bottle.

Fill the sample bottles immediately

Use a clean bucket to collect water. Make sure not to scrape the bucket against the concrete wall when pulling it up.

Do not sample at a point where lots of debris have accumulated

The sample can be collected using any of the methods shown. Use the method that works best for your particular sampling site.

Never take a sample trom a stagnant pool that is not connected to the main flowing river

Wear protective clothing (waders and gloves) when sampling in polluted water

7. TEMPERATURE MEASUREMENTS: The Monitoring Schedule might request a water temperature reading. The procedure to take such a reading is as follows:

• Temperature should be measured directly in the water to be sampled or

• when collecting water in a beaker, first fill your sample bottle and then read temperature from water left in the beaker or

• measure the temperature in the water that is used to rinse the bottle

Record the reading on the Macro tag in the space for "remarks"

e ~~POISONOUS -:~9 JIJ I .I.UJI HI H IJ M I D£I'TH ENO IAMPL£0: P£Pnt:,t_.__ _ ___J

~~~~ AEMARKS'f 21 QC

8. HOW TO PRESERVE A MACRO SAMPLE:

Fill the sample bottle to approximately l cm below the neck of the bottle.

Take one ampoule containing preservative and lightly tap the bottom on a solid surface, or tap with your finger to allow all the liquid to run down to the wide part.

Hold the ampoule in one hand - use thumb and forefinger of the other hand to snap the top off.

The two halves of the ampoule are now dropped into the sample bottle.

Screw the cap on tightly and shake the bottle a couple of times.

22

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